加遮挡板后二元喷管的红外辐射特性数值模拟

在宽高比为6.33的圆转矩形二元喷管喷口处安装不同结构的下遮挡板。通过计算流体力学/红外辐射(CFD/IR)综合数值模拟的方法,获得加遮挡结构后二元喷管的红外辐射场分布特征,并对不同遮挡结构的红外辐射抑制效果进行比较。结果表明:遮挡板结构改变了二元喷管原有的对称结构的辐射场分布。它对喷管的尾焰以及内外壁面产生的红外辐射在-90°~0°方向上有着较好的抑制作用。尾焰红外辐射强度最多降低51%,喷管内壁面红外辐射被完全遮挡。而双层遮挡结构可以削弱二元喷管-90°~0°方向43%的总体红外辐射,与此同时却增强了0°~90°方向40%的红外辐射。

Numerical simulation on the infrared radiation characteristics of two-dimensional nozzles with sheltering baffles

Different sheltering baffle structures were installed at the exit of 2-D circular to rectangular nozzles.The ratio of the nozzle exit was 6.33.The infrared radiation field characteristic and the effect on the infrared radiation suppression of different sheltering baffle structures were studied and compared by CFD/IR numerical simulation.The results show that the symmetry radiation field distributions of 2-dimensional nozzles are changed by sheltering baffle.They suppress the infrared radiation of plume and interior solid wall from the angle-90° to 0°.Compared with the normal 2-D nozzle,the infrared radiation intensity of plume decreases with 51%.The nozzle interior wall radiation is sheltered completely.Two-layer sheltering baffle reduces 43% radiation intensity of 2-dimensional nozzles at the angle-90° to 0°.Meanwhile it increases 40% radiation intensity at the angle 0° to 90°.